Selective Photobleaching of Chlorophylls and Carotenoids in Photosystem I Particles under High-Light Treatment
| Autor: | Atanaska Andreeva, Silvia Abarova, Katerina Stoitchkova, Rafael Picorel, Maya Velitchkova |
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| Rok vydání: | 2007 |
| Předmět: |
Chlorophyll
Lutein Light Electrons macromolecular substances Photochemistry Photosystem I Photosynthesis Biochemistry chemistry.chemical_compound Spinacia oleracea Physical and Theoretical Chemistry Carotenoid chemistry.chemical_classification Photobleaching Photosystem I Protein Complex food and beverages Pigments Biological General Medicine Carotenoids chemistry Spectrophotometry Photoprotection Xanthophyll sense organs |
| Zdroj: | Photochemistry and Photobiology. 83:1301-1307 |
| ISSN: | 1751-1097 0031-8655 |
| Popis: | Photosystem I particles (PSI-200) isolated from spinach leaves were studied by means of absorbance, 77K fluorescence and resonance Raman (RR) spectroscopy. The aim was to obtain better insight into the changes of the pigment spectral properties in those particles during prolonged exposure to high-light intensities and to reveal the involvement of these pigments in the photoprotection of the PSI. During prolonged exposure to high-light intensities of spinach PSI particles, a loss of a significant amount of photosynthetic pigments was observed. It was shown that various pigments exhibited different susceptibility to photodamage. In addition to bleaching of chlorophyll a (Chl a), bleaching of carotenoids was also clearly observed. RR technique allowed us to recognize the type and conformation of photobleached carotenoid molecules. Raman data revealed a nearly full photobleaching of the long-wavelength lutein molecules. The observed similar bleaching rate of the lutein molecules and the most-red shifted long-wavelength Chl a, located in the antenna membrane protein Lhca4, suggested that these molecules are located closely. Our results showed that the photobleached antenna pigments and especially luteins and the most long-wavelength absorbing chlorophylls are involved in photoprotection of PSI core complex. |
| Databáze: | OpenAIRE |
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